1. Field of the Invention
The present invention relates to the use of enantiomer-enriched ligands of the general formula I and their salts ##STR2##
in which
R.sup.1, R.sup.2, R.sup.3 signify, independently of each other, H, NR.sup.6 R.sup.7, SR.sup.6, (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, (C.sub.1 -C.sub.8)acyloxy, which can be optionally present as linear or branched and can be substituted singly or multiply with halogens, with groups containing N, O, P, S atoms, PA1 (C.sub.3 -C.sub.7)-cycloalkyl, which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, which can be optionally substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring such as 1-, 2-, 3-, 4-piperidyl, such as 1-, 2-, 3-pyrrolidinyl, 2-, 3-tetrahydrofuryl, 2-, 3-, 4-morpholinyl, PA1 (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl, (C.sub.6 -C.sub.18)-aralkyl, such as benzyl or 1,1-, 1,2-phenethyl, (C.sub.5 -C.sub.18)-heteroaryl, such as 2-, 3-furyl, 2-, 3-pyrrolyl, 2-, 3-, 4-pyridyl, PA1 (C.sub.6 -C.sub.18)-heteroaralkyl, such as furfuryl, pyrrolylmethyl, pyridylmethyl, 1-, 2-furylethyl, 1-, 2-pyrrolylethyl, 1-, 2-pyridylethyl, which aryl, aralkyl, heteroaryl or heteroaralkyl groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, PA1 or R.sup.1 and R.sup.2 are joined in a (C.sub.3 -C.sub.7)-carbocycle which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can optionally be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring, PA1 R.sup.4 signifies (C.sub.1 -C.sub.8)-alkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl, 2,2'-biphenyl or anthryl,1-pyrrolyl, and the just-cited groups can be optionally substituted with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, PA1 (C.sub.3 -C.sub.7)-cycloalkyl, which can be singly or multiply substituted with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be optionally substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring, PA1 R.sup.5 signifies H or a group B--X--Z in which B is a group selected from CR.sup.8.sub.2, NR.sup.8, O, S, and SiR.sup.8.sub.2, X is a spacer such as, e.g., 1,4'-biphenyl, 1-, 2-ethylene, 1-, 3-propylene, PEG-(2-10) and Z is a group bound to a polymer via a functional group such as, e.g., the O--, NH--, COO--, CONH--, ethenyl--, NHCONH--, OCONH-- or NHCOO-- function, or the groups R.sup.5 of the two cyclopentadienyl rings are connected to each other via an .alpha., .omega.-(C.sub.2 -C.sub.4)-alkylene bridge, PA1 R.sup.6, R.sup.7 signify, independently of one another, H, (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, (C.sub.1 -C.sub.8)-acyl, which are optionally linear or branched and can be singly or multiply substituted with halogens, with groups containing N, O, P, S atoms, PA1 (C.sub.3 -C.sub.7)-cycloalkyl, which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be optionally substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring such as 1-, 2-, 3-, 4-piperidyl, such as 1,2-, 3-pyrrolidinyl, 2-, 3-tetrahydrofuryl, 2-, 3-, 4-morpholinyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl, (C.sub.6 -C.sub.18)-aralkyl, such as benzyl or 1,1-, 1,2-phenethyl, (C.sub.5 -C.sub.18)-heteroaryl, such as 2-, 3-furyl, 2-, 3-pyrrolyl, 2-, 3-, 4-pyridyl, (C.sub.6 -C.sub.18)-heteroaralkyl, such as furfuryl, pyrrolylmethyl, pyridylmethyl, 1-, 2-furylethyl, 1-, 2-pyrrolylethyl, 1-, 2-pyridylethyl, PA1 which aryl, aralkyl, heteroaryl or heteroaralkyl groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, PA1 or R.sup.6 and R.sup.7 are joined in a (C.sub.3 -C.sub.7) carbocycle, which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can optionally be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, and/or can contain heteroatoms such as N, O, P, S in the ring, and PA1 R.sup.8 signifies H, (C.sub.1 -C.sub.8)-alkyl for homogeneous, catalytic, enantioselective hydrogenation. PA1 R.sup.1 to R.sup.8 have the meanings indicated above and M is a metal atom or metal ion of the subgroup [B group] 8, e.g., Ni, Co, Rh, Ru, Ir, Pd, Re or Pt for enantioselective, homogeneous, catalytic hydrogenation. PA1 R.sup.1, R.sup.2, R.sup.3 signify, independently of each other, H, NR.sup.6 R.sup.7, SR.sup.6, halogen, (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, (C.sub.1 -C.sub.8)-acyloxy, which can be optionally present as linear or branched as well as can be substituted singly or multiply with halogens, with groups containing N, O, P, S atoms, PA1 (C.sub.3 -C.sub.7)-cycloalkyl, which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, which can be optionally substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring such as 1-, 2-, 3-, 4-piperidyl, such as 1-, 2-, 3-pyrrolidinyl, 2-, 3-tetrahydrofuryl, 2-, 3-, 4-morpholinyl, PA1 (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl, (C.sub.6 -C.sub.18)-aralkyl, such as benzyl or 1,1-, 1,2-phenethyl, (C.sub.5 -C.sub.18)-heteroaryl, such as 2-, 3-furyl, 2-, 3-pyrrolyl, 2-, 3-, 4-pyridyl, PA1 (C.sub.6 -C.sub.18)-heteroaralkyl, such as furfuryl, pyrrolylmethyl, pyridylmethyl, 1-, 2-furylethyl, 1-, 2-pyrrolylethyl, 1-, 2-pyridylethyl, which aryl, aralkyl, heteroaryl or heteroaralkyl groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, PA1 or R.sup.1 and R.sup.2 are joined in a (C.sub.3 -C.sub.7)-carbocycle which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can optionally be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring, PA1 R.sup.4 signifies (C.sub.1 -C.sub.8)-alkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl, 2,2'-biphenyl or anthryl,1-pyrrolyl, and the just-cited groups can be optionally substituted with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, PA1 (C.sub.3 -C.sub.7)-cycloalkyl, which can be singly or multiply substituted with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be optionally substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring, PA1 R.sup.5 signifies H or a group B--X--Z in which B is a residue of the group CR.sup.8.sub.2, NR.sup.8, O, S, SiR.sup.8.sub.2, X is a spacer such as, e.g., 1,4'-biphenyl, 1-, 2-ethylene, 1-, 3-propylene, PEG-(2-10) and Z is a group bound to a polymer via a functional group such as, e.g., the O--, NH--, COO--, CONH--, ethenyl-, NHCONH--, OCONH-- or NHCOO-- function, or the groups R.sup.5 of the two cyclopentadienyl rings are connected to each other via an .alpha., .omega.-(C.sub.2 -C.sub.4)-alkylene bridge, PA1 R.sup.6, R.sup.7 signify, independently of one another, H, (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, (C.sub.1 -C.sub.8)-acyl, which are linear or branched and can be singly or multiply substituted with halogens, with groups containing N, O, P, S atoms, PA1 (C.sub.3 -C.sub.7)-cycloalkyl, which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be optionally substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms and/or can contain heteroatoms such as N, O, P, S in the ring such as 1-, 2-, 3-, 4-piperidyl, such as 1, 2-, 3-pyrrolidinyl, 2-, 3-tetrahydrofuryl, 2-, 3-, 4-morpholinyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl, (C.sub.6 -C.sub.18)-aralkyl, such as benzyl or 1,1-, 1,2-phenethyl, (C.sub.5 -C.sub.18)-heteroaryl, such as 2-, 3-furyl, 2-, 3-pyrrolyl, 2-, 3-, 4-pyridyl, (C.sub.6 -C.sub.18)-heteroaralkyl, such as furfuryl, pyrrolylmethyl, pyridylmethyl, 1-, 2-furylethyl, 1-, 2-pyrrolylethyl, 1-, 2-pyridylethyl, which aryl, aralkyl, heteroaryl or heteroaralkyl groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, or R.sup.6 and R.sup.7 are joined in a (C.sub.3 -C.sub.7) carbocycle, which can be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can optionally be substituted singly or multiply with halogens, groups containing N, O, P, S atoms, with halogens, with groups containing N, O, P, S atoms, and/or can contain heteroatoms such as N, O, P, S in the ring, and PA1 R.sup.8 signifies H, (C.sub.1 -C.sub.8)-alkyl, PA1 R.sup.1, R.sup.2 signify, independently of one another, H, N (C.sub.1 -C.sub.8)-alkyl.sub.2, NH (C.sub.1 -C.sub.8)-acyl, N (C.sub.1 -C.sub.8)acyl.sub.2, O (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which can be linear or branched, (C.sub.3 -C.sub.7)-cycloalkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl, PA1 R.sup.3 signifies (C.sub.3 -C.sub.7)-cycloalkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl and the just-cited groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, with halogens, PA1 R.sup.4 signifies (C.sub.1 -C.sub.8)-alkyl, (C.sub.3 -C.sub.7)-cycloalkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl and the just-cited groups can optionally be singly or multiply substituted with linear or branched (C.sub.1 -C.sub.8)-alkyl, with halogens, and PA1 R.sup.5 signifies H. PA1 R.sup.1, R.sup.2 signify, independently of one another, H, O (C.sub.1 -C.sub.8)-acyl, N (C.sub.1 -C.sub.8)-alkyl.sub.2, (C.sub.1 -C.sub.8)-alkyl, PA1 R.sup.3 signifies (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl and the just-cited groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, with halogens, PA1 R.sup.4 signifies phenyl, PA1 R.sup.5 signifies H. PA1 R.sup.1 to R.sup.8 have the meanings indicated above and M is a metal atom or metal ion of subgroup 8, e.g., Co, Ni, Rh, Ru, Ir, Pd, Re, for the homogeneous, catalytic, enantioselective hydrogenation of C.dbd.C and C.dbd.N double bonds. The coordination sites of central atom M left free in the general formula for the complex (II) in accordance with the invention and indicated above are ligands known to the expert in the art for this reaction (R. Schrock, J. A. Osborn, J. Am. Chem. Soc. 1971, 93, 2397-2407; R. Glaser, S. Geresh, J. Blumenfeld, J. Organomet. Chem. 1976, 112, 355-360) or possibly fill out the solvent present during the reaction. The coordinators are to be imagined for the corresponding formula (II). PA1 R.sup.1, R.sup.2 signify, independently of one another, H, N (C.sub.1 -C.sub.8)alkyl.sub.2, NH (C.sub.1 -C.sub.8)-acyl, N (C.sub.1 -C.sub.8)-acyl.sub.2, O (C.sub.1 -C.sub.8)-acyl, (C.sub.1 -C.sub.8)-alkyl, (C.sub.1 -C.sub.8)-alkoxy, (C.sub.2 -C.sub.8)-alkoxyalkyl, which are linear or branched, (C.sub.3 -C.sub.7)-cycloalkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl, PA1 R.sup.3 signifies (C.sub.3 -C.sub.7)-cycloalkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl and the just-cited groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, with halogens, PA1 R.sup.4 signifies (C.sub.1 -C.sub.8)-alkyl, (C.sub.3 -C.sub.7)-cycloalkyl, (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl and the just-cited groups can optionally be singly or multiply substituted with linear or branched (C.sub.1 -C.sub.8)-alkyl, with halogens, PA1 R.sup.5 signifies H. PA1 R.sup.1, R.sup.2 signify, independently of one another, H, O (C.sub.1 -C.sub.8)-acyl, N (C.sub.1 -C.sub.8)-alkyl.sub.2, (C.sub.1 -C.sub.8)-alkyl, PA1 R.sup.3 signifies (C.sub.6 -C.sub.18)-aryl, such as phenyl, 1-, 2-naphthyl or anthryl and the just-cited groups can optionally be substituted singly or multiply with linear or branched (C.sub.1 -C.sub.8)-alkyl, with halogens, PA1 R.sup.4 signifies phenyl, PA1 R.sup.5 signifies H.
Moreover, the invention concerns the use of enantiomer-enriched complexes of the general formula II and their salts ##STR3##
in which
2. Background Information
The homogeneous, catalytic, enantioselective hydrogenation of imines and enamines is of great interest for the production of, e.g., amino acids enriched with enantiomers since the latter are required for their part as chiral educts in the organic synthesis, e.g., of bioactive active substances.
The use of bisphosphine catalysts for the enantioselective, homogeneous, catalytic hydrogenation for the purpose just cited is well known (Burk et al., Tetrahedron 1994, 4399).
Hayashi et al. (J. Chem. Soc., Chem Commun. 1989, 495-496), Knochel et al. (Chem. Eur. J. 1998, 4, 950-968) and Ikeda et al. (Tetrahedron Lett. 1996, 4545-4548) describe Pd complexes with C.sub.2 -symmetric ferrocenyl-(bis-tertiary phosphine) ligands. However, these complexes were used solely in asymmetric allylations and cross couplings. The use of ligands in enantioselective hydrogenation was not known up to the present.
Yamamoto at al. (Bull. Chem. Soc. Jpn. 1980, 53, 1132-1137) reported about the use of non C.sub.2 -symmetric ferrocenyl-(bis-tertiary phosphine) ligands in enantioselective, homogeneous, catalytic hydrogenation. However, good excesses of enantiomers are obtained only very sporadically with these ligands.